• Xiaolin Zhang's avatar
    drm/i915/gvt: enabled pipe A default on creating vgpu · 7e605902
    Xiaolin Zhang authored
    when i915 driver unloading, it will shutdown all CRTCs and
    it will introudce kernel panic when conducting igt drv_module_reload
    test case under guest environment (bug reported by XENGT-468) as below:
    
    BUG: unable to handle kernel NULL pointer dereference at 0000000000000070
    IP: intel_edp_backlight_off+0xe/0x7c [i915]
    RIP: 0010:intel_edp_backlight_off+0xe/0x7c [i915]
    Call Trace:
     intel_disable_ddi+0xb3/0xbc [i915]
     intel_modeset_setup_hw_state+0x654/0xb4c [i915]
     intel_modeset_init+0x9f1/0xe69 [i915]
     ? intel_i2c_reset+0x3d/0x40 [i915]
     ? intel_setup_gmbus+0xba/0x249 [i915]
     i915_driver_load+0xae5/0xcc0 [i915]
     i915_pci_probe+0x3a/0x3c [i915]
     local_pci_probe+0x38/0x7b
     pci_device_probe+0xec/0x12b
     driver_probe_device+0x134/0x294
     __driver_attach+0x6a/0x8c
     ? driver_probe_device+0x294/0x294
     bus_for_each_dev+0x68/0x80
     driver_attach+0x19/0x1b
     bus_add_driver+0xea/0x1d3
     ? 0xffffffffa03cd000
     driver_register+0x85/0xc1
     ? 0xffffffffa03cd000
     __pci_register_driver+0x55/0x57
     i915_init+0x57/0x5a [i915]
     do_one_initcall+0x8a/0x12e
     ? __vunmap+0x8d/0x93
     ? kmem_cache_alloc_trace+0x96/0x11c
     do_init_module+0x5a/0x1e1
    
    in this case, active connector detected but no active pipe
    available, so it will hang to disable connector.
    
    to fix, on vgpu creating, to report active pipe available for
    guest.
    Signed-off-by: default avatarXiaolin Zhang <xiaolin.zhang@intel.com>
    Signed-off-by: default avatarZhenyu Wang <zhenyuw@linux.intel.com>
    7e605902
display.c 13.5 KB